arch/x86/purgatory/Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2
   3 purgatory-y := purgatory.o stack.o setup-x86_$(BITS).o sha256.o entry64.o string.o
   4
   5 targets += $(purgatory-y)
   6 PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
   7
   8 $(obj)/string.o: $(srctree)/arch/x86/boot/compressed/string.c FORCE
   9         $(call if_changed_rule,cc_o_c)
  10
  11 $(obj)/sha256.o: $(srctree)/lib/crypto/sha256.c FORCE
  12         $(call if_changed_rule,cc_o_c)
  13
  14 CFLAGS_sha256.o := -D__DISABLE_EXPORTS -D__NO_FORTIFY
  15
  16 # When profile-guided optimization is enabled, llvm emits two different
  17 # overlapping text sections, which is not supported by kexec. Remove profile
  18 # optimization flags.
  19 KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%,$(KBUILD_CFLAGS))
  20
  21 # When LTO is enabled, llvm emits many text sections, which is not supported
  22 # by kexec. Remove -flto=* flags.
  23 KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS))
  24
  25 # When linking purgatory.ro with -r unresolved symbols are not checked,
  26 # also link a purgatory.chk binary without -r to check for unresolved symbols.
  27 PURGATORY_LDFLAGS := -e purgatory_start -z nodefaultlib
  28 LDFLAGS_purgatory.ro := -r $(PURGATORY_LDFLAGS)
  29 LDFLAGS_purgatory.chk := $(PURGATORY_LDFLAGS)
  30 targets += purgatory.ro purgatory.chk
  31
  32 # These are adjustments to the compiler flags used for objects that
  33 # make up the standalone purgatory.ro
  34
  35 PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel
  36 PURGATORY_CFLAGS := -mcmodel=small -ffreestanding -fno-zero-initialized-in-bss -g0
  37 PURGATORY_CFLAGS += -fpic -fvisibility=hidden
  38 PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING
  39 PURGATORY_CFLAGS += -fno-stack-protector
  40
  41 # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
  42 # in turn leaves some undefined symbols like __fentry__ in purgatory and not
  43 # sure how to relocate those.
  44 ifdef CONFIG_FUNCTION_TRACER
  45 PURGATORY_CFLAGS_REMOVE         += $(CC_FLAGS_FTRACE)
  46 endif
  47
  48 ifdef CONFIG_STACKPROTECTOR
  49 PURGATORY_CFLAGS_REMOVE         += -fstack-protector
  50 endif
  51
  52 ifdef CONFIG_STACKPROTECTOR_STRONG
  53 PURGATORY_CFLAGS_REMOVE         += -fstack-protector-strong
  54 endif
  55
  56 ifdef CONFIG_MITIGATION_RETPOLINE
  57 PURGATORY_CFLAGS_REMOVE         += $(RETPOLINE_CFLAGS)
  58 endif
  59
  60 ifdef CONFIG_CFI_CLANG
  61 PURGATORY_CFLAGS_REMOVE         += $(CC_FLAGS_CFI)
  62 endif
  63
  64 CFLAGS_REMOVE_purgatory.o       += $(PURGATORY_CFLAGS_REMOVE)
  65 CFLAGS_purgatory.o              += $(PURGATORY_CFLAGS)
  66
  67 CFLAGS_REMOVE_sha256.o          += $(PURGATORY_CFLAGS_REMOVE)
  68 CFLAGS_sha256.o                 += $(PURGATORY_CFLAGS)
  69
  70 CFLAGS_REMOVE_string.o          += $(PURGATORY_CFLAGS_REMOVE)
  71 CFLAGS_string.o                 += $(PURGATORY_CFLAGS)
  72
  73 asflags-remove-y                += $(foreach x, -g -gdwarf-4 -gdwarf-5, $(x) -Wa,$(x))
  74
  75 $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
  76                 $(call if_changed,ld)
  77
  78 $(obj)/purgatory.chk: $(obj)/purgatory.ro FORCE
  79                 $(call if_changed,ld)
  80
  81 $(obj)/kexec-purgatory.o: $(obj)/purgatory.ro $(obj)/purgatory.chk
  82
  83 obj-y += kexec-purgatory.o